1. Field of the Invention
The present invention relates to a method for fabricating an electrode of an external electrode fluorescent lamp (EEFL) and, more particularly, to a method of fabricating an electrode of an EEFL that can be applied to a backlight unit used as a light source of a flat display device, wherein the method can easily form an electrode of a phosphor lamp to improve the quality and productivity of the fluorescent lamp and can improve the hardness of the external electrode. The present invention further relates to an EEFL having an electrode fabricated using the method.
2. Description of Related Art
Generally, an EEFL includes a glass tube in which a discharge gas, which is a mixture of neon and argon, and mercury are injected. The EEFL has a fluorescent layer formed on the inside wall of the glass tube, and external electrodes are disposed at both ends of the EEFL. An external electric power source may be provided to the external electrodes for causing an electric discharge of the EEFL. The external electrodes may be formed by dipping both ends of the EEFL into a ceramic solder bath in which tin, zinc, aluminum, antimony, and the like are added for a certain period. However, a protective cap covers each external electrode of the EEFL to protect the external electrodes. The protective cap may be formed of a material such as brass electroplated with nickel, or SUS. The protective caps cover the external electrodes after coating silver or carbon pastes on the electrodes. Then, the protective caps are heated by, for example, ultrasonic waves, so that the protective caps are firmly connected with the glass tube.
The protective caps make the manufacturing process of the EEFL complicated. Particularly, the manufacturing cost is increased since the protective cap needs to be prepared as an additional part.
In addition, after the dipping process is performed, pores may be formed during hardening of the ceramic solder. Therefore, in order to minimize the generation of the pores, vibration is applied during the dipping using an ultrasonic wave generator.
As described above, when using the ultrasonic wave generator, the generation of pores can be reduced. However, due to high viscosity of the protective cap material, the ultrasonic waves cannot propagate to a sufficient distance, and therefore, a large-sized ultrasonic wave generator has to be used in order to increase ultrasonic wave propagation efficiency.